Title: VoIP Performance on Differentiated Services Enabled Network

Abstract:
In this  talk we study the performance of Voice over Internet Protocol
   (VoIP) traffic aggregates over Differentiated Services (Diffserv) enabled
   network using Expedited Forwarding (EF) per hop behavior (PHB). We compare
   the delay and jitter performance of the VoIP traffic generated by different
   standard voice codec algorithms, both under
   Diffserv with EF PHB and with best-effort service.
   Both homogenous and heterogenous voice traffic aggregates
   are considered. Our results show that the use of EF yields
   very good performance improvement for voice traffic compared
   to best-effort. The improvement is greatest for high coding
   rate algorithms like G.711 than lower coding rate
   algorithms like G.723.1. For heterogenous traffic
   aggregates, the traffic from higher bit rate codecs
   obtains better performance compared to lower bit rate codecs.

Biography:
Dr. Muppala received the Ph. D. degree in Electrical Engineering from Duke
   University, Durham, NC in 1991.

   He is currently an associate professor in the Department of Computer
   Science,The Hong Kong University of Science and Technology, Clear Water Bay,
   Kowloon, Hong Kong.

   He was previously a Member of the Technical Staff at Software Productivity
   Consortium (Herndon, Virginia, USA) from 1991 to 1992, where he was involved
   in the development of modeling techniques for systems and software. While at
   Duke University, he participated in the development of two modeling tools,
   the Stochastic Petri Net Package (SPNP) and the symbolic Hierarchical
   Automated Reliability and Performance Evaluator (SHARPE), both of which are
   being used in several universities and industry in the USA.

   He was the program co-chair for the 1999 Pacific Rim International Symposium
   on Dependable Computing held in Hong Kong in December 1999 and has served on
   program committees of several international conferences.